My major research efforts center on defining the mechanisms of brain evolution. I believe the comparative method is the most reasonable approach, and that the mechanisms of brain evolution can best be understood by examining the variation and phylogenetic history of the brains of living vertebrates. In this application I outline a plan for continuing my efforts to characterize the anatomical organization of the amphibian telencephalon, utilizing autoradiographic and horseradish peroxidase methods, in order to contrast and elucidate the neural mechanisms that characterize the changes seen from amphibians to more advanced land vertebrates. As it is possible that the morphological organization of amphibians may be degenerate, thus biasing the analysis, it is also necessary to examine other closely related generalized anamniotic vertebrates in order to strengthen the basis for comparing amphibians to more advanced land vertebrates. The African lungfish, Protopterus, is chosen for comparison as it is most closely related to the fossil crossopterygians that gave rise to amphibians and because it possesses similar neural organization to the living crossopterygian, Latimeria. Since Latimeria is known from a very few specimens and cannot be utilized for experimental studies, comparison of the lungfish, Protopterus, with amphibians provides the strongest base for further comparisons with more advanced land vertebrates.